Aircraft wheel brakes are known that comprise a support receiving at least one electromechanical actuator fitted with a pusher that is movable facing friction elements in order to apply a braking force selectively thereto. In general, the actuator is reversible and it is fitted with a blocking member for blocking the pusher in position such that the pusher can be blocked while it is exerting a force on the friction elements.
The blocking member serves to provide a parking function, which consists in exerting a force on the friction elements when the aircraft is stationary and switched off. For this purpose, at least one actuator is operated so that its pusher exerts a force on the friction elements, the blocking member is activated to block the pusher in position, and the power supply to the motor of the actuator is switched off. In practice, the blocking member is a failsafe brake that releases the pusher when the blocking member is powered, but that blocks the pusher when the blocking member is no longer powered. The electrical power supply of the aircraft can then be disconnected, the parking force being provided even though the motor of the actuator and the blocking member are themselves no longer powered.
Under normal circumstances, even in the absence of braking, the actuator member is powered, and as a result so that the actuator consumes electrical energy.
Nevertheless, other situations exist in which the blocking member can be activated even though the aircraft is not electrically powered. Whereas under normal circumstances the blocking member is powered so as to leave the pusher free to move, it is possible when the aircraft is stationary and the pilot presses against the brake pedals for quite a long time, for the motors of the actuators to heat up needlessly. It is therefore known, in particular from document FR 2 880 602, to pass automatically into parking mode when activating the blocking member, i.e. when switching off its power supply. The pusher of the actuator is then blocked in position and the power supply to the motor of the pusher can then also be switched off. Under such circumstances, the actuator no longer consumes energy, while nevertheless maintaining a force on the friction elements.